1. Field of the Invention
The present invention relates generally to a data translation apparatus in a mobile communication system, and more particularly, to a data translation apparatus of asynchronous transfer mode (ATM).
2. Description of the Related Art
Recently, as the transmission of traffic information, for example, voice and data, is getting faster in public land mobile network (PLMN), ATM data is being recommended for faster data transmission in IS-95C systems based on a code division multiple access (CDMA) method. IS-95C is one of the digital-based cellular standards of the Telecommunications Industry Association/Electronic Industries Association (TIA/EIA) Interim Standard IS-95series (IS-95A, IS-95B and IS-95C) (also known as CDMA2000) entitled Mobile Station—Base Station Compatibility Standard for Dual-Mode Wideband Spread Spectrum Cellular System. Such a trend is now found in a mobile switching center (MSC), a base station controller (BSC), and even a base transceiver subsystem (BTS, also called base station transceiver subsystem). Besides, the transmission method in the PLMN is being changed similar to all Internet protocol (IP). In case of the CDMA system, although a systematic scheme concerning the all IP network in 3rd generation partnership project (3GPP) or 3rd generation partnership project 2 (3GPP2) is getting into shape, it will still take a while before it is actually put to practical use. Right now, it is only being realized as a proprietary protocol in a particular section.
As described above, the signal and information path among the MSC, the BSC and the BTS is mainly on the basis of the ATM method (in case of a physical layer protocol (PHY), E1 (European digital line interface) is usually used). A configuration of MSC and BSC combined system can be formed over an IP network between systems. The IP network is now explained. First of all, a base station is connected to terminals through antennas via a wireless link. Also, the base station is connected to a cell controller through an ATM-E1 (asynchronous transfer mode-European digital line interface) link. Therefore, the base station and the cell controller take an H/W (hardware) shape or the program itself is designed to be able to process the ATM data. Here, the cell controller is connected to an access G/W and an air agent through an IP network to a call agent and a media G/W. In this manner, the cell controller is connected to the public switched telephone network (PSTN) at its end.
Especially when the BTS is changed to the IP connection as described above, the H/W shape of the BSC or the program should be designed again, but unfortunately when doing so, a lot of problems have been discovered. That is to say, to accomplish a more stabilized operation between the BTS and the BSC, a number of systems' performance should be tested, and if in any case there is a problem, H/W (hardware) or S/W (software or program) necessary to the systems should be redesigned and the stabilization test should be conducted again. This naturally required a lot of human resources and time, and of course additional costs thereby. Primarily, it is that way because the IP and the ATM use completely different techniques from each other, and changing one single component cannot just solve all problems.